Laptop continuously restarting

Hello,
Its me sanjeed again..!
Your web is really helping everyone a lot.
I appreciate it. But,my laptop Acer Aspire 5742 is still not working. I deassembled
My laptop.the keyboard was not connected. So, i connected it and tried to boot it up with windows 8 pro.
But, its not coming. It just hangs when the windows logo appear. And it restarts again and again. What can i do...plzz help me... I beg uu.....plzzz
Immediately.... I hope u will help me in this

Reading the symptoms that you share, I think the problem could be found on the hard drive. Please, try with a Windows repair CD if you have one or make a USB bootable flash if you haven't. The Windows .iso file must be the same bit version as yours installed on the hard drive of the lapp.
Try to boot from it and to repair the OS. You could do that by opening the Command prompt console and entering the following command followed by Enter:
sfc /scannow

Sometimes, windows restart again and again when you select the option of "restart automatically". You must uncheck this option by following these steps.
Start > Control Panel > System, in System Properties click the Advanced tab, then under ''Startup and Recovery'' click the ''Settings'' button, and remove the tick in the option ''Automatically restart''.
It will resolve your issue.

Another issue of computer hanging is when you use heavy antivirus. Used avast trial system, it is cleaned and also using malwarebytes also cleaned